Active noise cancellation

• Active Noise Cancellation technology is designed to remove or reduced the background noise so that you can have great listening experience even in the noisy environment.
• Active Noise Cancellation technology which is used in high-end earphones and headphones in fact the same technology is also used in the smartphones and because of this technology we are able to hear the crystal clear voice of the person during the call.
• Every earphones and headphones provides some sort of messy noise cancellation and the passive noise cancellation is the noise that headphones blocks out based on the physical designed of the earcups so the shape of the headphones and how it fits over the head determines how much noise the headphones can block out so by any means this passive noise cancellation technology cannot block the background noise completely.
• So the active noise-cancelling headphones which has miniature microphones in the earpiece that picks up the ambient noise and the electronics in the earpiece creates the noise cancelling wave that is 180 degree out of phase with the ambient noise so this wave acts like a noise eraser or anti noise and cancels out the surrounding noise without diminishing the audio that you want to hear and because of this technology one can enjoy the music in the noisy environment so this active noise cancelling headphones are widely used in the aviation industry.

Different types of active noise cancellation techniques

a) The feed forward noise cancellation

 In a feed forward set up the microphones is placed outside the ear cup so these mic monitors the external noise and active noise cancellation circuits invert the noise into the anti noise and then it is mixed with the audio playback to create the noise cancellation now in this techniques has the mic picks up the noise early on it has a more time to respond and generate the anti noise and because of this it is good for the high frequency noise reduction.

b)The feedback-end noise cancellation

 In this type of noise cancellation technique the microphone is fitted inside the ear cup itself and as it is in front of the speaker it hear the resulting signal in exactly the same way the user does and because of that it can add up the variation in the noise easily. This feedback type of anti noise cancellation can only cancel the low frequency noise so to enhance the frequency range of the noise cancellation hybrid systems are used which combines both feed forward and feedback system.

c) The hybrid noise cancellation

In this techniques the microphones are placed inside as well as outside the ear cup and as it combines both feed forward and the feedback system the frequency range of the noise cancellation will also increase but at the same time these headphones are b quite expensive and bulky and usually they are only preferred for the specific applications.